GPS Problem Solved!

After a month of struggling with trying to figure out why I had no GPS data, I discovered the following tip in the APM manual. I tried this and it solved my problem. As they say, RTFM. Thanks again to everyone who has tried to help me figure out my GPS problem over the past month.

From the APM Manual:

Note: in the 1.0 Beta code there is a slight bug in the MediaTek setup routine, which requires you to reset your board after a cold start before the GPS lock will be registered. So if you're using the MediaTek GPS, wait until the blue lock LED on that module goes solid, then press the reset button on your APM board or shield. This will do a warm start of the board, and the LED behavior should be as shown in the table above.

Replies to This Discussion

I would also suggest that for a more accurate RTL position, that you wait a further 60 seconds after first fix is acheived (blue LED goes solid) before resetting to allow the GPS to lock more satellites and get a more accurate fix. An initial 3D fix can be as bad as 50m accuracy but once the GPS pulls in some more sats this should quickly improve to much greater accuracy.

That is good to know! I was just wondering about this today. I'm very new to all of this, so I did not know how accurate the RTL was supposed to be. During the past few days of testing my APM I noticed that RTL was not very accurate. I have not been waiting very long to reset the APM after GPS lock. I'll definitely wait a bit longer from now on, Thanks

I believe Im having this problem myself with an mtek gps on my arducopter though it doesnt seem like the reset routine is fixing the problem. See the overlay attached. It should look like a T with the path following the dock. Can someone elaborate about the problem or possible fixes?